Support



Aug. 24, 1937. P. 'II'HOMSON SUPPORT Filed. Sept. 22, 1936 FIG. 2.

2 Sheets-Sheet 1 INVENTOR.

FETEI" THEI'I'FLEUT'L' 36 W W ATTORNEY P. THOMSON SUPPORT Filed Sept. 22, 1936 FIG. 5;

45 FlG.7.'

2 Sheets-Sheet 2 I INVENTOR.

1 ET 21- Thclms c111 ATTORNEYS.

Patented Aug. 24,- 1937 uNirE STATES PATENT oi-"FirE 4 Claims.

This invention relates to the trestles or sup ports of scaffolds and the like, and more particularly to extensible trestles.

An important object of the invention is to provide a trestle which, while extensible, is very sturdy. Frequently, extensible trestles, adapted to support scaffolding, are not steady and. when weight is placed upon the scaffold, the latter rocks and may cause the securing and bracing members of the trestle associated therewith to work loose so that the scaffolding collapses. The novel trestle herein disclosed, retains the scaffold floor boards support timber against movement, even when subjected to heavy weights, and there is no tendency of the securing or bracing members to work loose.

Another important object is to provide an easily set up and knock-down trestle.

Still another object is to provide a device of this kind which may be manufactured at low cost and comprises but few and simple parts.

Yet another object is to provide a trestle for association with scaffolding, the construction of the trestle being such that both longitudinal and transverse swaying of the scaffolding will be prevented.

Other objects and advantages of the invention will be apparent during the course of the following detailed description, taken in connection with the accompanying drawings, forming a part of this specification and in which drawings:

Figure 1 is a front elevation of the novel trestle.

Figure 2 is an end elevation of the same, secured to a portionof the scaffolding.

Figure 3 is a rear elevation of the novel trestle.

Figure 4 is a fragmentary view, from the rear, of the novel trestle, extended to a greater height. Figures 5 and 6 are sections upon substantially their respective lines of Figure 1.

Figure 7 is a section upon substantially the line '!'i of Figure 2.

Figure 8 is a section upon substantially the line 88 of Figure 3.

Figure 9 is an elevation of the member shown in section in Figure 8.

In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of the invention and wherein similar reference characters designate corresponding parts throughout the several views, the letter A may designate generally the novel trestle or support and the letter B a suitable member forming a portion of the scaifolding.

The trestle or support A preferably includes a pair of main supports or legs Ill, which may be of angle iron. When the trestle is set up these supports ID are disposed so as to converge upwardly, as shown in Figures 1, 3, and 4, but they 5 do not cross one another. The supports iii are arrangedso that an outer angle iron face I! of each is in substantially a common plane, and the inner angle iron face i2 of the other leg of the angle of each support faces the other. With this arrangement a similar edge iii of each support faces the other. While the upper extremity it of this edge i3 may be beveled, so to provide a cutting edge,-it has been discovered that the wall of the angle iron is thin enough so that, when 15 a suitable member B, such as of wood, is placed between the supports, at their upper ends, and these ends are drawn towards each other, the extremities I4 of the edges l3 will bite; into. the member B.

'A horizontally disposed cross piece or member I5 is provided, bridging the supports It, below and adjacent the upper ends thereof, as shown for example in Figures 1 and 3. This cross piece l5 preferably comprises a' fiat bar or strip of metal provided with an upper edge l6 which may be serrated or toothed, as shown at IT.

Means for securing this cross piece l5, either pivotally or rigidly, to the supports I0 is provided and may comprisea bolt 20 extending through one support Ill and the cross piece I5 adjacent one end thereof, and a second bolt 2i extending through the other support it and the cross piece l5 adjacent the other end thereof. Each bolt is provided with a suitable nut 22. So that there may be some adjustment of the length of the cross piece I! between the two supports ill, one or more extra perforations 23 may be provided extending through the cross piece l5, so as toaccommodate the shank of the bolt 2|. When the nuts 22 are not tightened upon their respective bolts, there is a pivotal connection between the support It] and the cross piece'l5, but when the nuts are well'tightened, there is a rigid connection.

' Means for spreading and bracing the supports I0 is provided and preferably comprises a lever 25 which may be a suitable length of metal bar, pivoted at one end 26 to one support III, as by a bolt 2'! extending through. the lever 25 and support wall and, preferably, having a squared head 28 countersunk below the inner face of the Wall of the support ID, as shown in Figure 5. Pivotally connected to the lever 25 and the other support I0, is a link 29. As is well known in the construction of leverage devices of this kind, the link a 55 29 is pivotally connected to the lever 25 as shown in Figures 1 and 3. Preferably a suitable bolt 3|) extends through the lever 25, intermediate its ends, and through one end of the link 23, while another bolt 3| pivotally connects the other end of the link 29 to the second support I0, as shown particularly in Figure 5. Each of the bolts 21, 36, and 3| may be provided with suitable nuts 32, and a suitable spaced collar 33 may be disposed upon the shank of the bolt 3 I, between the link 29 and support ID, as shown in Figure 5, in order to space the link from the support ID a sufiicient distance so that the lever may be forced down between the two and come to rest upon the periphery of the collar 33. It is apparent that,

as the lever is pushed or drawn downwardly,-the I supports It] will spread apart at their lower ends and move towards each other at their upper ends until the lever comes to rest as heretofore de-- scribed. On the other hand, as the lever 25 is drawn upwardly, the supports l will be drawn towards each other at their lower ends and will spread apart at their upper ends.

Slidable along the inner faces of the angle iron supports II] are auxiliary supports 35, which may be angle iron of less width and length than the supports I5, as shown particularly in Figures 3, 5, and 8.

So that these auxiliary supports 35 may be employed, in order to lengthen the trestle A, and be held in place, a securing means is provided and preferably consists of a suitable section of mate rial, such as a short, flat strip 36 of metal which extends from one edge l3 to the other edge of each support ID, as shown in Figure 8, and may be welded thereto. At least two of such strips 36 are secured to each support l0, and spaced apart adjacent the lower end of the support. Each strip 36 may be provided with a suitable screw threaded perforation 31, midway its ends, through which extends a thumb screw 38, or the like, having a beveled free end so that it may engage and bear against the inner faces of the auxiliary angle iron supports 35 at the juncture of the two walls forming each auxiliary support.

Preferably, pivotally carried'by each support in, is one of a pair of arms 46 which may be of resilient metal. These are pivoted to the supports In, as shown particularly in Figures 1, 2, and 7, by bolts 4| extending through suitable perforations in the arms 40 and supports H], the heads 42 of these bolts being countersunk. Suitable nuts 43 are provided for the bolts 4|. For the greater portion of their length, these arms converge but do not meet. At their free ends 44, they are provided with suitable sharpened projections or teeth 45, which are disposed to point towards each other, since the free end-s 44 of the arms 40 parallel each other, as shown particularly in Figures 1, 3, and 'I. The arms 46 are joined together by a rod 46 extending through them, having a head 41 at one end, screw threads 41 at the other end, and a nut, such as a wing nut 48, to cooperate with these screw threads 41 to draw the two end-s 44 of the arms towards each other when the wing nut 48 bears against one of the arms and the head 41 of the rod 46 bears against the other arm. When the wing nut 48 is unscrewed, the arms, due to their resiliency, will move away from each other.

It is apparent that, with these bolt and nut connections, the trestle A may be disassembled in order to form a compact bundle for shipping and storage, yet the trestle may be quickly and easily set up again. r

With the trestle A set up as shown in Figure 1, and the nuts 22 loosened so that the shanks of the bolts 20 and 2| provide pivots for the supports l3 and cross piece l5, and the lever 25 swung upwardly, a suitable member B, such as a plank 53, may be dropped into place upon the toothed edge of the cross piece l5. By now bearing down upon the lever 25, the supports l will move towards each other at their upper ends and the edges !4 will bite into the opposite faces 5| of the plank 56, and at the same time, due to the are described by these edges I4, the plank will be forced down upon the teeth I! of the cross piece l5. The nuts 22 may now be tightened upon their respective bolts 20 and 2|, so that there is a --rigid connection between the supports l6 and cross piece l5.

By swinging the arms 43 upwardly so that a portion of the free ends 44 are to either side of the plank 46 and face the opposite faces 5| thereof, the free ends may be struck by a suitable tool so as to force the teeth 45 into the plank 53, and the free ends may be secured in contact with the plank by tightening up on the wing nut 48 upon the screw threaded end of the rod 46.

' It is apparent that the bolt 2| may be inserted into the perforation 23 of the cross piece |5in order to lengthen the distance between the'two" supports ID at the cross piece l5, so as to accommodate planks of different thicknesses and regulate the extent the edges M will bite into the plank.

In order to lengthen the trestle A, the thumb screws 38 may be loosened so that the auxiliary supports may be slidably extended from the lower end of the main supports l6, whereupon the screw threads 38 may be again tightened when the extended trestle has reached its proper height;

- Even when exceptionally heavy weight or high pile of material are placed upon the scaffold platform supported by the member B, there will be no dangerous side or longitudinal sway of the scaffold and, as a consequence, the various bolted connections will not work loose, nor will other types of screw threaded and similar connections work loose. This absence of side and longitudinal sway is due to the method of providing a biting contact with the sides and bottom of member 3 and. the bracing effect of the arms 40. A mere contact of supports or cross pieces with the membe'rB will not obviate dangerous side and longitudinal sway and it is also important that, the pivotal connection provided by the bolts 20 and 2| between the supports l0 and the cross piece l5 be changed to a rigid connection by tightening upon the bolts 22 or when the trestle has been finally adjusted, as has been described.

Various changes may be made to the form of invention herein shown and described, without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. 'In an adjustable trestle, a pair of supports converging upwardly, a cross piece bridging said supports below and adjacent the upper ends thereof and having a serrated upper edge,'means for selectively securing said cross piece rigidly and pivotally to said supports, and means for spreading and bracing said supports, disposed below said cross piece, whereby when a suitable member is placed upon said cross piece and said supports are spread apart at their lower ends and are drawn towards each other at their upper ends, by said last named means, said member will be forced down upon said serrated edges by said upper ends coming into contact with said member.

2. In an adjustable trestle, a pair of supports converging upwardly and each provided with a biting edge at its upper end, a cross piece bridging said supports below and adjacent said biting edges, said cross piece having a toothed upper edge, means for selectively securing said cross piece rigidly and pivotally to said supports, and means for spreading and bracing said supports, disposed below said cross piece, whereby, when a suitable member is placed upon said cross piece and said supports are spread apart at their lower ends by said last named means, said biting edges will enter said member and said member will be forced down upon said toothed edge and retain said member rigidly upon said cross piece.

3. In an adjustable trestle, a pair of supports converging upwardly, each of said supports comprising an angle iron with an edge of one support facing a like edge of the other support, a cross piece bridging said supports adjacent their upper ends, said cross piece having a serrated upper edge, means for selectively securing said cross piece rigidly and pivotally to said supports, and means for swinging said supports upon their pivotal connections with said cross piece, including a lever disposed below said cross piece and operatively connected with said supports, whereby when said lever is in one position said edges of said angle irons will move towards each other and toward said serrated edge of said cross pieces at the upper ends of said supports so that a suitable member disposed upon said serrated edge will be forced by said edges, at the upper ends of said supports, downwardly upon said a' serrated edge.

4. In a scaffolding trestle, a pair of upwardly converging supports, means connecting said supports adjacent their upper ends, a pair of arms of resilient material secured to said supports and extending upwardly and away therefrom, said arms converging towards one another and each being provided with a tooth at its free end, said teeth pointing towards one another, and means for moving the free ends of said arms and said teeth towards one another.

PETER THOMSON. 

